We use these for skiing and they are great! Just make sure to put the shiny side down. Also as you are putting them in your boots - don't wait too long between opening the package and putting them in because they can poof up (but that goes away after you put your foot on them and put weight on them). The M/L fits my shoes (women 9) and my husbands (men 9) great.
In subzero weather driving the Polaris to clean the snow off of the driveway or going shopping these are great even without socks they keep my feet toasty warm. I only wish I could have found them for my husband when he was doing chores and digging us out of the snow on our farm all those many long years. If your wondering how long they last after two hours cleaning the driveway I came in and removed them from my snow boots and stuck them in my slippers and they kept my feet warm until I went to bed about 8 to 10 hours after I opened them. I cant see living up here without them ever again.
These things work as expected. The intent is to keep your feet at body temperature. I just used these over the weekend on days where the temperature was ZERO... they worked. I like the fact there are no wires (I have ski boot heaters with wires and BIG batteries). The smartest way to use these insoles is to put them on medium to get the maximum time.
My husband is a hunter and when you hunt in ND at this time of the year, your feet get cold when you are out for extended periods of time. He has enjoyed the warmth of these inserts and will be happy to have them when he is our snow-blowing too!
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